Signaling system



June 'i F326.

A. M. CURTS SGNALING SYSTEM Filed August 19, 1924 Ala/.sien /Vl rCMM/ls r circuit of amplifier tube 8 and the input 'cir- 4position for receiving end no further change 'plifieiav4 cuit of amplifier, tubes 9 and 10 which hare takes plgice until it isdesired to switch from their elements connected in parallel to pro-A the receiving to the,sendingposition. l

ride a larger output. Coupling condensers i When itis desired to switch to the sending 411-11 and shunt condcnseis 12-12 are prolposition the handle 15 is slowly operated in vided between stages as shown.

:in anti-clockwise. directionf As the brush The change from sending to receiving positions and vi'ce rcrsa, is accomplished by trom batterv 21 to wn'iding'QS), segment 23,

21 engagesseginent 23 a circuit/is closed means ofsnjitch S comprising' :1 handle 15'by brush 21y and segment 2 2 back'to the batteryi means oi' which the brush 16 successively lthus'energizing the armature SOY'and causing.

connects segment 1T with segments 18, l9` it to engage with Contact lend place a andQO, while brush Q1 connects segment 22 `short circuit.` across lthe interstage transwitli segments 2 and 2l. -The 'coi'iductor of vformer 32 As rotation continues, brush 16 cable C is connected to seg-nient li' while' the passes from ,segnient 20- to segment 19 thus groundedtraiisuiittcrfll is 'connected to segdisconnecting the network from the cable ment 1S and ione `terininal of the shaping conductor which now connected to earth. IIGWOlkis connected to. segment 20. Digrlhe cable conductor remains connected to nient 19 is grounded and thesea ground earth untilhrush x16 passes from segment 19 25 ot' the cable G is connected as to segment' 1S thus removing the earth conshown Atok U10 Shaping! nctworkc Segment nei-tron and connectingtransniitter T to the 252 is' connected to ihc common poi1it`0f cable conductor.; The switching mechanism batteries Q6 and 2 7, ythe other' terminals ot" Slis so designed-'that aperiodr ot'approxiwhich.u'eonnccted tlu'oilg'lri'elay `{iiiriflini lnmielyten ASeconds n uqf be caused t0 elapse 28- and QS respectively-"to segments 2l and during changing f ro'iii one position to an- 2-3. The relayai'iiiature 30, when in' engageother thus providingltime for the vdraining nient with the 'contactl is'lzidapted to place' of the greater portion ot' the cl'ia'i'ge absorbed a short-circuit across the primary Winding 'by the cable (E lhe relay which controls the andadded'priinnry resistance of the .auto Shop@ ciu-uitingv of' the' mnplifgr' is 50 arf tlllSfOllHeI DOSODed bGWCII ilRHlt ranged that. thearmature.remains'in whatand second stages oi the aniplifienv There. 'ever position'f-it .was `lnstt`eiiergized- This ceivingr'nicclninisiii'R;A which'ii'i generahjufill 'may be accomplished: hy"employin g separate consist vof a siph'on recorder', is connected in' f ldng-s fis 'shoirn or h y-'tlie'iiseofa polarn thc output ciiciii't'of the last stage ofthe am? ized relay,

' Q v w For the With the brush arm intheiiositon Shown, necessary rimini@ slim-t. circuit be applied the circuit .is arranged for sendingF current between vthe trstiiid.second fstages of 'the most 'satisfactory o-ieratioiu it is;

.conductor oli-cable' C; The sli'api'ngl network plied '-:icross -the seconf l 'a1 y"coil-ofthel input i'itn'ined'nntil v.atteiand thearuiatureBO is in engagement with, the Shock. ca.us cd bv applying-the 'resid-m5 contact lfthus placing' ai short-circuit neross cablovoltage 'to thc's.

iapinghetirork.hns dis:-

i the amplifier. Jlt' the handle LS'is operated appearothtlie initial hoek to -theamplifier I j 'throiigh relay winding; 28 causing-the urina--l died destina irealt iiiipiilse'.iiiay still Vb e'jpro'- Aina clockwise direction,l the hrushlG passes" noiildbe. avoided.' biitasft-l'icrc are ale" frimi. scgmentlS onto segmentlt) thus dis- ,cin-rents.of1; `ve1-y .low fifqu oncy Hou-mgm vconnectingr vthe transmitter"l` trom segment relayibuifiio change 'takes place in this rclay transients eli'c since the impulse' is in the direction lo iniln;*piiticifn'hi't tam the-arniature inA engagement,with con' denser the cable net'ujorka'udthe reiner-al or. applilirhich. isgconnected to the cable comV u ctor cation ofthe shoit'circuit to the tri'nst'ormcr und connectingthe-cable lo groundthrough, secondary changes thenetworkconstantsl and segment lili Upon.further rotatioin the cathe-.earth current abriiptly',iiii impulse ,or blc continues grounded imtilbruslr-16 passes .oscillation is'slill produced nn-i batteryA 2f! iliriuigliftlie winding; 29 of the fthe. cable-tolt-heampli-lier'prokhilfesn'merely l.

onfllie' inst ,tz'ietjSL In the. last-stage of the switehinir i shorteirc i1 ited" tlie.pulso'-d'oes not .'.111 to segment 2t-andannnpul'se. is then sont 'oiiitis'reiiioyech after, the strong; .impulse has tlire-,Sftgbe operated. in the opposite direc-fduefed., due to .the application; ofthe current" openingfthe short-circuit across the intercondenser'ltothe auttransforiner primary .staffe transformer The s stein is new 'in jwindi'n eind4 e so diie toen flowwfre uenc v a y q y by breaking Contact with Blend 'leaking through, tlieirstinterst'ge,coupling earth currents or interference of higher frequencies which maj,y be present and impress a voltage between the first stage ot' the rac uum tube plate and its filament. This pulse however is usually of the saine order as the normal signal and docs not cause any daniage. If the short circuit is connected be tween the second and third or between the. third and fourth sta-ges o' the ainplilicr, the current.impulses/occurring at the time the short circuit is'q'emoved are of sullicicnt strength when aniplilied to override the C batteries and render the apparatus inoperative until the normal grid voltages are again established. While in the arrangement shown a rotatable switch is disclosed in oi'- der to more clearly indicate the sequence of thesteps in switching from sending to reyceiving positions or Vice versa, it will vbe understood that in operation, these switchingopera-tions may be performed automatically and in their correct sequence by means of relays.

What is claimed is z: e 1. In a signaling system comprising a cable, a sending' mechanism and' a receiving;` mechanism having an amplifier associated therewith, means for preventing excessive current impulses at the time of completing the circuit between the receiving mechanism and the. cable.

. 2. In a signaling system comprising a cable, a sending mechanism and a receiving 'mechanism having an amplilier associated therewith, means for bridging a low impedance circuit across the amplifier to prevent excessive currentimpulses at the time ot connecting the receiving; apparatus to the cable.

3. In a signaling system comprising' a cable, a sending mechanism and a receivingy mechanism having an amplifier associated therewith, an electromagnetic device operable during the time of connecting` 'the ainplifier and receiving mechanism to the line for short-circuiting the ampliiier.

4. In a signaling system comprising a cable, a sending mechanism, a receivingV mecln anism having an amplifier associated therewith and a switching mechanism for alternately connecting the sending mechanism and the receiving mechanism with its associated amplifier te the cable, an electromagnetic device under the control of said switching mechanism for protecting the amplifier and receiving mechanism from excessive cur- .reiit impulses occurring during the operation of the switchingmechanism.

5. In a signaling system comprisnw a cable, a sending mechanism, a receivingl mechanism having an amplifier associated' therewith and a switching mechanism ior alternately'ccnneeting the sending mecha.-vv lnisin and the receiving mechanism with. its asscociated amplifier to the cable, an electre9v magnetic device under the control of said switi'hlng iiiecliziiiisni for connecting a bridging circuit across lhc aiiipliliei' to i'ii'event the flow of eXcessire rnrreiit inipiilses therethroiigl'h during' the switching' operations.

(l. ln a signalingr s ysiein conipi'isinir'a cable, a sending; mechanism. a receiving,l mechanism haring an aniplilier associated therewith and a switching mechanism ifo'r alternately connecting the sendingy mechanisin and Athe receiving inccl anisni with its associated ai'nplilier to il cable` an electromagnetic device ior placing a short circuit bridge arrtss Jthe aniplilici' :it the instant ci connecting the ainplilier to the calle.

7. ln a sioiialiiie' system, comprising' a. cable, a #cociner mechanism. a receiving mechanism having an anipliicr associated therewith and a switching' mechanism for alternately connmtiifey thc sending i'nechaiiisin and the receivingA mechanism with its associated anipliliei lo the cable. an electromagnetic device aiiton'iaticail}r ontrtdled by the switching' n'icclianisni to short circuit the amplifier at the instant the cable is connected thereto.

8. ln a signaling?r system, a cable, a sending' mechanism, a receiving mechanism liavl ingr anvanipliier associated therewith, a switchingv mechanism ici' alternately con ncctingg thc sending' and 'receiving nicchanisnis to thc cable, and means Under the conirol oi' the switching; mechanism 'for rendering the amplifier inoperative at the instant the cable is connected thereto.

E). ln a signaling' system, a cable, Va sending mechanism, a receiving mechanism have ing an amplifier associated therewith, a

switching mechanism operable at the end of the sending' period for disconnecting t" c cable from the transmitting mechanism and connecting it to earth for a short interi/al before connecting it to ti e receiving mechanism, and means automat' ll;y operated by the switching mechanism 'tor short circuiting the amplii'ier until after the cable is 1 connected thereto.

il.. En a signaling system comprising, a. cable, a Sending mechanism, rcceiviiiff lill) mec'hanisi., a multistage'amplifier associated with said receiving, mechanism, and means for connecting short-circuit across said ainpliiicr to 'preventexcessive current celvmg mechanism to the cable.-

12.4 In n signaling' cable., n sending mecl ystem comprising a mmsm, a recelvlng 5 mechanism, a multi=stage amplifierassociated with said receiv means' for connecting a short circuit across the output 'circuit oefthe fst'sage of Sa In Witness whereof, I hereunto subscribe 1D any name thls 15th 'day of August 2.. D.,

AUSTEN M. CURTIS. 

